Shiladitya DasSarma (born November 11, 1957) is a molecular biologist well-known for contributions to the biology of

halophilic The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, ...

and extremophilic microorganisms. He is a Professor in the University of Maryland Baltimore. He earned a PhD degree in Biochemistry from the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

and a BS degree in Chemistry from

Indiana University Bloomington Indiana University Bloomington (IU Bloomington, Indiana University, IU, or simply Indiana) is a public university, public research university in Bloomington, Indiana. It is the flagship university, flagship campus of Indiana University and, with ...

. Prior to taking a faculty position, he conducted research at the

Massachusetts General Hospital Massachusetts General Hospital (Mass General or MGH) is the original and largest teaching hospital of Harvard Medical School located in the West End neighborhood of Boston, Massachusetts. It is the third oldest general hospital in the United Stat ...

Harvard Medical School Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...

, and

Pasteur Institute The Pasteur Institute (french: Institut Pasteur) is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who invented pasteurization and vaccines f ...

, Paris. DasSarma has served on the faculty of the

University of Massachusetts Amherst The University of Massachusetts Amherst (UMass Amherst, UMass) is a public research university in Amherst, Massachusetts and the sole public land-grant university in Commonwealth of Massachusetts. Founded in 1863 as an agricultural college, it ...

(1986-2001),

University of Maryland Biotechnology Institute Formed in 1985, the University of Maryland Biotechnology Institute (UMBI) is part of the University System of Maryland. It was created to provide a unified focus for Maryland Maryland ( ) is a state in the Mid-Atlantic region of the Unit ...

(2001-2010), and

University of Maryland School of Medicine The University of Maryland School of Medicine (abbreviated UMSOM), located in Baltimore City, Maryland, U.S., is the medical school of the University of Maryland, Baltimore and is affiliated with the University of Maryland Medical Center and Me ...

Institute of Marine and Environmental Technology
(2010–present). He is a researcher and teacher of molecular genetics,

genomics Genomics is an interdisciplinary field of biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes as well as its hierarchical, three-dim ...

, and

bioinformatics Bioinformatics () is an interdisciplinary field that develops methods and software tools for understanding biological data, in particular when the data sets are large and complex. As an interdisciplinary field of science, bioinformatics combi ...

and mentor of undergraduate, graduate and postdoctoral students, and junior faculty. He is widely known to have been instrumental in the foundation of the fields of

halophile The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, ...

and extremophile research.

Research

Halophiles

In early work (1980's), he discovered mobile genetic elements in halophilic Archaea, while a graduate student with H. Gobind Khorana (Nobel laureate) and Uttam L. RajBhandary at MIT. He also showed that transcriptional promoters in Archaea were different from those in common Bacteria, which contributed to the acceptance of the three Domain view of evolution proposed by

Carl Woese Carl Richard Woese (; July 15, 1928 – December 30, 2012) was an American microbiologist and biophysicist. Woese is famous for defining the Archaea (a new domain of life) in 1977 through a pioneering phylogenetic taxonomy of 16S ribosomal RNA, ...

. In the 1990s, he organized and led the team that deciphered the first genome sequence and genetic code for a halophilic microbe, ''

Halobacterium ''Halobacterium'' (common abbreviation ''Hbt.'') is a genus in the family Halobacteriaceae. The genus ''Halobacterium'' ("salt" or "ocean bacterium") consists of several species of Archaea with an aerobic metabolism which requires an environment ...

'' sp. NRC-1. This work showed that its proteins are highly acidic, providing an understanding of how proteins may function in high salinity and low water activity conditions. The genome sequence helped to further establish the validity of the Archaea through the finding of similarities to higher eukaryotic organisms and differences from Bacteria. Later in the 2000s, his work also suggested that certain genes are acquired through horizontal gene transfers, such as the genes for

aerobic respiration Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP. Cellular respiration may be des ...

. Post-genomic research in his laboratory established the core and signature proteins in halophilic Archaea, and the function of many genes and genetic elements, including multiple replication origins, general transcription factors, and

DNA repair DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA dam ...

systems.

Astrobiology

DasSarma's recent research (2010's) on an Antarctic halophilic microorganism, ''

Halorubrum lacusprofundi ''Halorubrum lacusprofundi'' is a rod-shaped, halophilic Archaeon in the family of Halorubraceae. It was first isolated from Deep Lake in Antarctica in the 1980s. Genome Several strains of ''H. lacusprofundi'' have been discovered. The genome ...

'', resulted in further refinement in understanding of protein function in a combination of high salinity and cold conditions. Such studies may explain how life could adapt to new environments, including extraterrestrial environments. DasSarma proposed that

retinal Retinal (also known as retinaldehyde) is a polyene chromophore. Retinal, bound to proteins called opsins, is the chemical basis of visual phototransduction, the light-detection stage of visual perception (vision). Some microorganisms use retin ...

pigments originally discovered in halophilic Archaea may have predated

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...

pigments in the early earth, named the " Purple Earth" hypothesis. This proposal provides a potential new

biosignature A biosignature (sometimes called chemical fossil or molecular fossil) is any substance – such as an element, isotope, or molecule – or phenomenon that provides scientific evidence of past or present life. Measurable attribute ...

for remote detection of life.

Biotechnology

DasSarma's laboratory has been instrumental in the study of buoyant gas vesicle nanoparticles ( GVNPs) in ''Halobacterium'' sp. NRC-1, and developed an expression system to bioengineer GVNPs for biotechnology applications. These

nanoparticles A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 1 ...

may represent a valuable platform for antigen delivery, vaccine development, and other biomedical and environmental applications

References

External links

* Halophiles Manual Cold Spring Harbor http://www.worldcat.org/title/halophiles/oclc/33850503 * Halophiles, eLS http://www.els.net/WileyCDA/ElsArticle/refId-a0000394.html * CBS Story http://baltimore.cbslocal.com/2013/03/14/researchers-study-survival-secrets-of-mars/ * Baltimore Sun Story http://www.baltimoresun.com/health/maryland-health/bs-hs-salt-vaccine-20120621-story.html * Haloarchaeal Genomes Website http://halo.umbc.edu/ {{DEFAULTSORT:DasSarma, Shiladitya 1957 births Living people Indian emigrants to the United States Indian molecular biologists Indiana University Bloomington alumni Massachusetts Institute of Technology School of Science alumni University of Massachusetts Amherst faculty University of Maryland, Baltimore faculty Scientists from Kolkata 20th-century Indian biologists Indian bioengineers